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A226273
Number of distinct values u^v, where u and v are digits occurring in decimal representation of n.
2
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 4, 3, 4, 4, 4, 4, 4, 3, 3, 4, 1, 4, 4, 4, 4, 4, 4, 3, 3, 3, 4, 1, 4, 4, 4, 4, 4, 3, 3, 4, 4, 4, 1, 4, 4, 4, 4, 3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 3, 3, 4, 4, 4, 4, 4, 1, 4, 4, 3, 3, 4, 4, 4, 4
OFFSET
0,11
COMMENTS
Row lengths in table A226272;
a(n) <= 61; A171102(1) = 1023456789 is the smallest number m such that a(m) = 61.
a(n) = 61 for almost all n, in the sense that the natural density of n such that a(n) < 61 is 0. - Charles R Greathouse IV, May 13 2015
LINKS
EXAMPLE
See A226272.
PROG
(Haskell)
a226273 = length . a226272_row :: Integer -> Int
(PARI) a(n)=if(n<9, return(1)); my(d=Set(digits(n)), v=List()); for(i=1, #d, for(j=1, #d, listput(v, d[i]^d[j]))); #Set(v) \\ Charles R Greathouse IV, May 13 2015
CROSSREFS
Sequence in context: A125087 A271373 A307558 * A111353 A038565 A344869
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Jul 09 2013
STATUS
approved